Precipitator3 Data Sections

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Precipitation3	Model Theory - Growth	Model Theory - PSD	Model Options	Data Sections	Dynamic Mode	Batch Operations (Probal)

Latest SysCAD Version: 25 October 2024 - SysCAD 9.3 Build 139.36522

Related Links: Alumina 3 Bayer Species Model

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Precipitator3 Tab

Unit Type: Precipitator3 - The first tab page in the access window will have this name.

Tag (Long/Short)	Input / Calc	Description/Calculated Variables / Options
Tag	Display	This name tag may be modified with the change tag option.
Condition	Display	OK if no errors/warnings, otherwise lists errors/warnings.
ConditionCount	Display	The current number of errors/warnings. If condition is OK, returns 0.
GeneralDescription / GenDesc	Display	This is an automatically generated description for the unit. If the user has entered text in the 'EqpDesc' field on the Info tab (see below), this will be displayed here. If this field is blank, then SysCAD will display the UnitType or SubClass.
Requirements
On	Tick Box	This can be used to take a precipitator off line. When a precipitator is not ON, the input stream will act as though it has bypassed the precipitator, thus no change will occur in this unit. This option is useful for feasibility studies of flowsheet configuration.
TankBypass	Tick box	Feed bypasses entirely to Product, tank contents continue to react. Dynamic only
Bypass	Tick box	Allows bypassing of a fraction of feed directly to outlet. Bypassing for more information. In Dynamic mode, this represents short-circuiting of feed to product, so will only occur while the tank is overflowing, else all feed is added to tank contents.
BypassFraction	Input	How much of the feed to bypass, visible if Bypass is on.
TankVol	Input	The precipitation tank volume, used to calculate the residence time.
LevelControl	Tick Box	Enable tank level control. Dynamic only with Underflow connection.
Level.Spt	Input	Target level for level control. Dynamic only with LevelControl enabled.
Level.QvMin	Tick Box	Minimum underflow flowrate for level control. Dynamic only with LevelControl enabled. Default 0.
Level.QvMax	Tick Box	Maximum underflow flowrate for level control. Dynamic only with LevelControl enabled. Default '*' (unrestricted).
BatchMode	Tick Box	Adds the Batch & Cycle tabs. The precipitator model will operate in a pseudo-dynamic batch mode, simulating a tank which is filled with separate feed and seed streams, allowed to precipitate, then drained. See Batch Mode for more information.\\
EnthalpyCalcs	Original (Hz)	Original option for compatibility with older projects. To be deprecated.
	Managed HOR (Hs)	User-Specified Reaction Heats. Discussion Page New Reaction Heat Features in Alumina Precipitation Models
	Species DB HOR (Hf)	Reaction Heats Determined from Species Data H25.
Cooling	None	No cooling required.
	Embedded	Uses embedded cooler for cooling. User do not need to add the cooler unit. A Cooler Tab becomes visible and can be configured. See also Cooler Options for more information.
	External	Uses external cooler for cooling. User will need to add the cooler unit separately. A Cooler Tab tab becomes visible and can be configured. See also Cooler Options for more information.
Reactions	Off	No extra reactions
	On	This allows the user to add extra reactions to the model. Note that THA precipitation and Soda co-precipitation are built-in reactions, user do not need to specify these. When this option is on, RB becomes visible and may be configured. See Reactions for more information.
Classification	Tick Box	Only relevant if unit has an Underflow connection (from Build 139, the Classification option does not appear unless this is connected) Adds the Classif tab. Allows Solid and liquid separation using an internal General Separator model. See Classification for more information.
ThermalOverride	None	Don't override.
	TempDrop	Overall heat loss based on Temperature Drop. Note that calculated HOR and cooling effects are ignored as this temperature drop is applied as an overall override.
	ProductT	Specify the product temperature.
TempDropReqd / TDropReqd	Input	The overall temperature drop required, visible with the TempDrop ThermalOverride Method.
TemperatureReqd / T_Reqd	Input	The overall exit temperature required, visible with the ProductT ThermalOverride Method.
ThermalLossMethod (Only visible if the ThermalOverride is set to NONE.)	None	No additional heat loss to the environment or thermal balance overrides.
	TempDrop	Additional heat loss based on Temperature Drop. In this case the temperature drop is applied on top of HOR and cooling effects.
	FixedLoss	Additional heat loss is expressed as a fixed amount of energy.
	Ambient	Additional heat loss is expressed as Energy/degree of temperature difference to ambient.
	WindAmbient	More detailed ambient model accounting for wind speed. See Thermal Loss Method for equation and limits.
	WindAmbient2	More detailed ambient model accounting for wind speed. See Thermal Loss Method for equation and limits.
TempDropReqd / TDropReqd	Input	The temperature drop required (for energy loss not necessarily the overall tank temperature drop), visible with the TempDrop Method.
ThermalLossReqd	Input	The amount of energy to be lost to the environment, visible with the FixedLoss method. (Positive for heat outflow)
ThermalLossAmbient	Input	The amount of energy per degree to be lost to the environment, visible with the Ambient method.
LocalWindSpeed	Tickbox	Visible with the WindAmbient ThermoLossMethod. Selecting this option allows user to use a local wind speed, this could be different than that specified in the Plant Model - Environment tab. If it is not selected, then the value specified in the Plant Model - Environment will be used.
WindSpeedUsed	Result	Displays the actual wind speed used.
WindLossRateK	Input	Rate, visible if WindAmbient option for thermal loss is selected.
TankSurfaceArea	Input	Tank external surface area including both top and side, visible if WindAmbient option for thermal loss is selected.
LocalAmbientT	Check Box	Allow individual tank specification of ambient temperature. If off, PlantModel.Environment.T is used.
AmbientT.Reqd	Input	Local ambient temperature for thermal loss and evaporation calculations using Ambient. Visible if LocalAmbientT is enabled.
Evaporation	None	No evaporation loss to the environment.
	Fixed	Fixed evaporation rate. Suggested values are in the range 0.25 to 1.0 t/h.
	Ambient	Fixed evaporation rate per degree of temperature. Suggested values are in the range of 0.005 to 0.025 t/h.K.
Evap.Rate	Input	The evaporation rate required, visible with the Fixed Method.
Evap.Per.degK	Input	The evaporation rate required per degree of temperature, visible with the Ambient method, or overall constant for detailed model.
ProdGasEntrainment	Input	The fraction of vapours which report to the Product stream rather than the Vent. This includes any vapours from the feed stream or gases evolved from reactions. This excludes water from evaporation. Default 0%.
OperatingP - NOTE: this pressure is applied to the (combined) feed, before sub-models (if any).
Method	AutoDetect	If there are any liquids AND no vapours present in the feed, outlet streams will take the highest pressure of the feeds. Else (e.g. some vapours present) outlet streams will take the lowest pressure of the feeds.
	LowestFeed	Outlet streams will take the lowest pressure of the feeds.
	HighestFeed	Outlet streams will take the highest pressure of the feeds.
	Atmospheric	Outlet streams will be at Atmospheric Pressure. The atmospheric pressure is calculated by SysCAD based on the user defined elevation (default elevation is at sea level = 101.325 kPa). The elevation can be changed on the Environment tab page of the Plant Model.
	RequiredP	Outlet streams will be at the user specified pressure.
IgnoreLowMassFlow / IgnoreLowQm	Tick Box	This option is only visible if the AutoDetect, LowestFeed or HighestFeed methods are chosen. When calculating the outlet pressure and temperature of the tank, SysCAD will ignore the low flow feed streams should this option be selected. The low flow limit is set in the field below.
LowMassFlowFrac / LowQmFrac	Input	This field is only visible if the IgnoreLowQm option is selected. This is the amount any stream contributes to the total flow. For example, if the total feed to the tank is 10 kg/s, and this field is set to 1%. Then any feed streams with less than 0.1 kg/s will be ignored in the pressure calculations.
PressureReqd / P_Reqd	Input	This field is only visible if the RequiredP method is chosen. This is user specified pressure.
Result	Calc	The actual pressure used for the sum of the feeds which will also be the outlet pressure (unless further model options change the pressure).
PresetData (Dynamic Only)
UsePresetImg	Tickbox	Selecting this option will add the Preset + DSp Tabs, allowing user to define a pre-made mixture to be used to preset the contents of the precipitator.
Temperature / T	Input	User specified preset Temperature, used when the preset tank command is executed.
Level / T	Input	User specified preset level, used when the preset tank command is executed.
Options
ShowQFeed	Tick box	Switches on the QFeed tab pages to display the total feed stream properties into the Precipitator. This is useful if more than one Feed streams are connected to the precipitator. See Material Flow Section.
ShowQTank	Tick box	Visible if Bypass is on. Switches on the QTank tab pages to display the tank contents exit stream properties before adding the bypass to give the exit stream (QProd). See Material Flow Section.
ShowQEvap	Tick box	Visible if Evaporation method selected. Switches on the QEvap tab pages to display stream details of the evaporated water. See Material Flow Section.
ShowQVent	Tick box	Visible with Vent connection. Switches on the QVent tab pages to display the vent stream properties from the Precipitator. This may include water vapour from evaporation. See Material Flow Section.
ShowQProd	Tick box	Switches on the QProd tab pages to display the product stream properties from the Precipitator. This may include vent gases if no Vent stream connected. See Material Flow Section.
ShowQTubeIn	Tick box	Visible if embedded cooling. Switches on the QTubeIn tab pages to display cooling tubes inlet stream properties. See Material Flow Section.
ShowQTubeOut	Tick box	Visible if embedded cooling. Switches on the QTubeOut tab pages to display cooling tubes outlet stream properties. See Material Flow Section.
Results Tank
ResidenceTime	Calc	The calculated residence time of the slurry in the unit.
TotalMass / Mt	Calc	The total mass of the slurry in the unit.
SolidMass / SMt	Calc	The mass of the solid in the unit.
Eff.ResidenceTime	Calc	Effective solids residence time from Classification. Note: when classification is used, solids have a longer residence time due to internal recycle.
Level	Calc	Tank level as fraction of volume. Dynamic Only
QmAcc	Calc	Nett inflow rate Dynamic Only
MtAcc	Calc	Nett inflow Dynamic Only
SSN_Ratio / SuperSat	Calc	The Supersaturation = Product A/C divided by Equilibrium A/C = (A/C) / (ASat / C@25). This is the same as the ratio of A to ASat. A and C are referenced to 25°C.
Solids.Conc	Calc	The solids concentration in the unit referenced to 25°C.
Yield (in grams Al2O3 per liter liquor @ 25C)
Yield	Calc	The calculated Yield = Gibbsite precipitated as equivalent Alumina per unit volume of feed liqour at 25°C. Note: in Dynamic, this is the difference in THA between feed and product streams, and may be negative or meaningless if tank is filling or in batch operation.
YieldRate	Calc	Rate of increase in THA solids (gpl/hr) Dynamic Only
THA.Precip	Calc	The mass of Trihydrate Alumina Al[OH]3 precipitated in the unit.
Al2O3.Precip	Calc	The mass of Trihydrate Alumina Al[OH]3 precipitated in the unit, expressed as Al2O3.
Solids.Precip	Calc	The mass of solids precipitated in the unit, includes THA, bound soda and bound organics.
Oxalate (Only visible if the oxalate precipitation is on.)
Oxalate.Precip	Calc	The mass of oxalate precipitated in the unit.
Oxalate.Yield	Calc	The mass yield of oxalate in the tank (g Na2C2O4 / L liquor). Only shown in Steady State.
Oxalate.Solubility	Calc	The oxalate solubility at equilibrium (g Na2C2O4 / L).
Oxalate.SSN	Calc	The oxalate relative super saturation level (Ox / Ox* - 1).
Results
MassFlowIn / Qmi	Calc	The mass flowrate at the inlet conditions.
MassFlowOut / Qmo	Calc	The mass flowrate at the Product Stream. Note: If the classification option is on, this shows the classifier overflow (product) flowrate. The underflow flowrate is shown under the Results Underflow section.
MassFlowLoss / QmLoss	Calc	This shows the mass flow difference between inlet and outlet streams. If vapour is present (due to reactions or evaporation) and the vent stream is not connected, then the vapour will be discarded, the mass imbalance value will be shown here.
VolFlowIn / Qvi	Calc	The volumetric flowrate at the inlet conditions.
VolFlowOut / Qvo	Calc	The volumetric flowrate at the outlet conditions.
BypassQm	Calc	The mass flowrate of the bypass material.
BypassQv	Calc	The volumetric flowrate of the bypass material.
TemperatureIn / Ti	Calc	The inlet temperature.
TemperatureOut To	Calc	The outlet Temperature.
ACin	Calc	The A/C ratio at the inlet conditions.
ACout	Calc	The A/C ratio at the outlet conditions.
ACequil / ACSat	Calc	The A saturation at the outlet conditions to C concentration at 25 °C.
BoundSodaFraction	Calc	(The bound soda and bound organics precipitation rate expressed as Na2O) / (THA precipitation rate expressed as Al2O3).
BoundSodaPrecip	Calc	The bound soda precipitation rate. If NaOH*(s) is present in the project, this will show the bound soda as NaOH, otherwise this will show bound soda expressed as Na2O. The total bound soda/organic precipitated = BoundSodaPrecip + BoundOrganicsPrecip
BoundSodaPerTHA	Calc	(The bound soda precipitation rate expressed as "boundsodaspecies") / (THA precipitation rate expressed as Al[OH]3). The bound soda species is shown in the Bound Soda Calculations section.
BoundOrganicsPrecip	Calc	The bound organic precipitation rate - expressed as the bound organic species, such as Na2C5O7*(s). The total bound soda/organic precipitated = BoundSodaPrecip + BoundOrganicsPrecip
Results Underflow Only visible with Classification option selected.
UF.MassFlow / UF.Qm	Calc	The mass flow of the underflow stream.
UF.SolidMassFlow / UF.SQm	Calc	The solid mass flow of the underflow stream.
UF.SolidFrac / UF.Sf	Calc	The solid mass fraction of the underflow stream.
UF.VolFlowOut / UF.Qv	Calc	The volumetric flow of the underflow stream.

Precip Tab

Tag (Long/Short)	Input / Calc	Description/Calculated Variables / Options
Precip.On	Tickbox	Enable precipitation chemistry functionality. Dynamic only
Precip.Method	SSA	Uses the specified seed surface area estimated from the input stream conditions. User can specify a SSA value by ticking the OverrideSSA option. NOTE: If there is a PSD in the feed, it will be removed from the outlet stream.
	PSD	Use the Full Particle Size Distribution (PSD). Refer to Alumina3 Precip - Full PSD for more information.
Hydrate Precipitation
GrowthMethod	Fixed	User specifies a fixed alumina precipitation rate (as a mass flow rate).
	FixedRate	The alumina precipitation rate is calculated from a fixed user specified growth rate.
	White-Bateman	The alumina precipitation rate is calculated using the White Bateman correlations [2]. See Growth Rate Theory for information.
	Veesler-Boistelle	The alumina precipitation rate is calculated using the Veesler Boistelle correlations [7]. See Growth Rate Theory for information.
	SSA Yield	The alumina precipitation rate is calculated taking into account factors of free caustic, total organic carbon, soda concentration and SSA. See Growth Rate Theory for information.
GrowthAsDeposition	Input	Removed in Build 139. Defines growth rate as radial/crystal growth (true) or diametric/particle growth (false).
UseCorrectedGrowthRate	Input	Available from Build 139. (May be visible if upgrading project.) Removes GrowthAsDeposition option - radial and diametric growth are both calculated and applied as required by different growth and agglomeration methods. Recommend this box be checked and model retuned if necessary.
GrowthRateCorr	Input	Growth rate correction factor, applied to all methods except Fixed.
VolumeCorrection	Tickbox	Reduces precipitation rate for alumina and bound soda to account for excess volume in Dynamic calculation step. May be useful for large time steps. Default off. Dynamic only
SeedSSA	Tickbox	Visible with Precip.Method set to SSA. If aluminate is available but no solid THA is present, this will seed a small arbitrary mass of THA and creates the SSA quality at 0.050 m^2/g. This can assist with start-up from reset.
OverrideSSA	Tickbox	Visible with Precip.Method set to SSA. Allows user to specify a SSA value for the precipitation tank. Any feed stream value will be ignored.
AdjustProdSSA	Tickbox	Adjust product stream SSA to account for particle growth (using spherical model). When using the SSA method, the adjusted product SSA = FeedSSA * [(FeedSolidMass/ProductSolidMass)^(1/3)] If unchecked, the product SSA will be the same as the feed SSA (when Precip.Method is StreamSSA) or the user specified SSA (when Precip.Method is UserSSA). Not visible when Precip.Method is FullPSD. In a full PSD model, the SSA may increase or decrease depending on the initial size distribution and the effects of nucleation and agglomeration, so this should be used with care.
UserFeedSSA / SSA	Input	The seed surface area specified directly by the user. Any SSA value, if present, in the feed stream is ignored. Visible when Precip.Method is SSA.
SSAin	Calc	The current SSA value from feed stream.
SSAUsed	Calc	The SSA value used in the calculations as per the above inputs.
THA.Density	Calc	The THA species solids density (used in GrowthRate calculation).
Variables for the Fixed GrowthMethod
Precip.Rate	Input	The user specified precipitation rate.
Variables for the FixedRate GrowthMethod
FixedGrowthRate	Input	The user specified growth rate.
Variables for the White-Bateman GrowthMethod
ER_White	Input	The Activation Energy (E) divided by the Gas Constant (R), in units Kelvin.
K_White	Input	The Constant used in the Growth Rate Factor correlation.
gF_White	Input	This allows the user to tune the growth rate based on a factor.
Variables for the Veesler-Boistelle GrowthMethod
ER_VB	Input	The Activation Energy (E) divided by the Gas Constant (R), in units Kelvin.
K_VB	Input	Overall growth rate constant.
Beta.Critical	Input	Critical supersaturation (nominally 1), must be exceeded for growth to occur
N_VB	Input	Exponent g for relative supersaturation term [math]\displaystyle{ (\beta-\beta_c)^g }[/math]
Variables for the SSA Yield GrowthMethod
ActivationEnergy/R	Input	The Activation Energy (E) divided by the Gas Constant (R), in units Kelvin.
K0	Input	The Constant used in the Growth Rate Factor correlation. Default value for K_0 is 2.2*1011. This value is typically tuned for plant conditions. It may need adjustment as additional terms described below are adjusted.
n_TOC	Input	Organics term = [math]\displaystyle{ e^{-n_{TOC} \quad \times \; TOC} }[/math]. Using zero for n_TOC will remove TOC dependence.
n_s	Input	Total Soda effect = Sn_s. Using zero for n_s will remove the precipitation dependence on soda.
n_fc	Input	Free Caustic – Free caustic is the sodium hydroxide in solution that is not associated with dissolved alumina. KFreeCaustic = FCn_fc.Using zero for n_fc will remove the precipitation dependence on free caustic.
n_C	Input	Additional Caustic effect term Cn_C. The default value is zero.
n_AC	Input	This is the n factor for the supersaturation driving force term. [math]\displaystyle{ \left( \frac{A_{out} - A^*}{C} \right)^n }[/math]. The default value is 2.
n_ssa	Input	Specific Surface Area, SSA. This correction accounts for the fact that the effective surface area for precipitation may not scale linearly with SSA. Kssa = SSAnssa. The default value for nssa is 1.0 (making precipitation rates linearly proportional to SSA).
GrowthMethod Results
kG	Calc	kG constant for the GrowthMethod
GrowthRateFactor	Calc	Product of kG and [math]\displaystyle{ e^{-E/RT} }[/math]
GrowthRateR	Calc	Radial (i.e. crystal) growth rate. This is the growth rate term multiplied against particle surface area to determine precipitation rate. See Growth Rate Methods for more details.
GrowthRateD	Calc	Diametric (i.e. particle) growth rate. GrowthRateD = 2 x GrowthRateR
Precip Heat of Reaction
UserHOR	Tickbox	Option for User to enter Heat of Reaction for Gibbsite Precipitation reaction (kJ/kg-Gibbsite). The default value is -252.3 kJ/kg-Gibbsite at 0°C. NB this is an exothermic reaction and energy is released as Gibbsite precipitates. For reference, please refer to Heat of Dissolution of Gibbsite and Boehmite
User.GibbsiteHOR@0C	Input	The Gibbsite precipitation HOR value to be used. Only available when UserHOR is selected. NB a positive entry generates a warning message as the HOR shold be negative. For reference, please refer to Heat of Dissolution of Gibbsite and Boehmite
GibbsiteHOR@0C	Calc	The Gibbsite precipitation HOR value used. -252.3 kJ/kg-Gibbsite at 0°C if UserHOR is not selected. For reference, please refer to Heat of Dissolution of Gibbsite and Boehmite
AluminaHORMethod	Input	Different Methods for specifying Alumina Heat of Reaction (New)
Bound Soda Calculations
BoundSodaMethod (Not visible with Fixed GrowthMethod)	Ohkawa	Ohkawa, Tsuneizumi and Hirao [5] method with corrections for bound soda as Na2O and NaOH* - now the default method. See Bound Soda Theory for information.
	Hunter	Armstrong, Hunter, McCormick and Warren. [6] correlation, see Bound Soda Theory for information.
	Fixed %	Calculates a fixed percentage of soda co-precipitation with the precipitated hydrate. This specifies soda as NaOH as a mass fraction of alumina as THA.
K_tuneBS	Input	The tuning factor for the bound soda calculation.
K1	Input	The soda factor. The default value is 1.27*10-3.
E_SODA	Input	Constant used in the bound soda calculation, default is 2535 K-1
BoundSodaFrac	Input	Visible when BoundSodaMethod is set to Fixed. The user specified bound soda fraction.
BoundSodaSpecies	Text	Display the bound soda species used for occlusion. If NaOH* is present, it will be used, if not, the project will use Na2O. If neither is present, the project will force add Na2O(s) to the species list.
BoundSoda_OrgPart	Input	The percentage of bound soda precipitated as organics. If the bound organic species is not present in the project, a warning message: Organics precipitation and BoundSoda_OrgPart not available:Matching bound organic solid for Na2C5O7(aq) not found will be given. See Bound organics for more information.
Oxalate Calculations
OxalatePrecip	None	No oxalate co-precipitation occurs.
	Fixed	Oxalate co-precipitation will occur at a user specified fixed rate.
	Supersaturation	The oxalate supersaturation form uses a driving rate proportional to the square of the oxalate supersaturation above an optional metastable value. Please note that this is only a made up equation with no theory or experimental data to support it. It is added here so the precipitation can be varied based on the tank conditions. For users with their own correlation data, it will be highly recommended to calculate the rate using general controller or MP file, then set the oxalate precipitation rate using the Fixed Method. See Oxalate Precipitation Theory for more information.
	McKinnon	McKinnon, Parkinson and Beckham [8] equation, see Oxalate Precipitation Theory for information.
OxalateReqd	Input	Visible with OxalatePrecip set to Fixed. User defines the amount of oxalate precipitation as a fixed amount. If user correlation is available, the oxalate precipitation can be calculated in a PGM or MP file using the correlation, then set the calculated rate here.
OxSSatReqd	Input	Oxalate supersaturation fraction (Ox / Ox* - 1) required for oxalate precipitation, used to account for metastability. Used by the Supersaturation method.
OxSSatK	Input	Constant used by the Supersaturation oxalate precipitation method.
OxalateRateFactor	Input	Oxalate precipitation rate tuning factor used by the McKinnon method.
Solution Convergence (Not visible if using Batch Mode)
UseLastConverged	Tickbox	If selected, will restart solution iteration at last converged state. If the solution is nearly converged, this will speed up the iteration. If the solution was converged, and nothing else is changed it should immediately converge.
Convergence.Limit	Input	Global tolerance for testing convergence for iterative calculation in all precipitator tanks. Default is 1.0e-8.
Thermal.Damping	Input	Damping for energy convergence. Default of 0.
Mass.Damping	Input	Damping for mass convergence. Default of 0. This value may need to be increased, often significantly 80% plus, for a precip tank with a significant change. Try increasing this when failed to converge error message is shown.
Ext.FlowDamping	Input	Damping for external cooling volume flow convergence when using external cooling. Default of 0.
ClassifierError	Tickbox	Include classifier recycle in overall convergence
NumberErrors	Tickbox	Include PSD numbers in overall convergence
PSDErrScale	Input	Relative Contribution of PSD Error
MinIterations	Input	Minimum number of iterations for the convergence loop.
MaxIterations	Input	Maximum number of iterations for the convergence loop.
Iterations	Calc	Number of iterations solved.
Yield Error	Calc	Error in convergence of yield calculations
PSDError	Calc	Error in convergence of particle numbers.
ClassifyError	Calc	Error in convergence of classifier recycle.
TotalError	Calc	Total Error.
Dynamic Time Step (Options for additional internal iterations at smaller time steps for dynamic calculation. Allows for higher precision precipitation in projects with large step sizes. Note: This may cause increased project solve time. Dynamic Only)
Safety.TimeStep	Iteration Count	Use a specified number of internal time steps. E.g. if the Dynamic Solver Step Size is 300s and IntegrationSteps = 5, then 5 internal time steps of 60s each will be used.
	Max Time Step	Use a specified maximum internal time step. The number of internal iterations will depend on the Dynamic Solver Step Size. Input value is local to the tank. E.g if the project time step is 300s and MaxTimeStep = 120s, then 3 internal time steps of 100s each will be used.
	Max Time Step Global	As with Max Time Step but the input value is global.
IntegrationSteps	Input	Input for Iteration Count.
MaxTimeStep	Input	Local input for Max Time Step.
Global.MaxTimeStep	Input	Global input for Max Time Step Global.
IntegrationStepsUsed	Calc	The number of internal time steps used. Visible with MaxTimeStep or Global.MaxTimeStep.
Thermal and Mass Balance
Env.Thermal.Loss	Calc	The amount of energy lost to the environment.
Evap.Mass.Loss	Calc	The evaporation mass rate
Evap.Thermal.Loss	Calc	The amount of energy lost through evaporation.
Batch.Evap (only visible if both the BatchMode and Evaporation options are ON)
Feed.Evap.T	Calc	the PGL feed temperature after evaporation (only visible if both the BatchMode and Evaporation options are ON)
Feed.Evap.DeltaT	Calc	the temperature drop in the feed stream (only visible if both the BatchMode and Evaporation options are ON)
Cooler.Thermal.Loss	Calc	The amount of energy transferred through the cooler.
Total.Thermal.Loss	Calc	Total amount of energy loss: Evap + Env + Cooler.
ReactionHeat@0	Calc	The amount of energy released by the precipitation reaction at the 0dC temperature.
ReactionHeat(@T)	Calc	The amount of energy released by the precipitation reaction at the product temperature.
Stream Enthalpy
HzIn	Calc	Enthalpy flux into Precipitator.
HzEvap	Calc	Enthalpy flux to Evaporation.
HzOut	Calc	Enthalpy flux of the product stream. If classifier option is being used, then this will only show the overflow stream, the underflow stream will be shown in UF.HzOut.
UF.HzOut	Calc	Enthalpy flux of the underflow stream. Only visible if classifier option is being used.
HzBal	Calc	Enthalpy out minus enthalpy in. This is the net of heat transfer, evaporation loss and reaction heat (NB Rxn heat measured at 0°C reference temperature).
FeedHf	Calc	The total energy of the feed.
ProdHf	Calc	The total energy of the product.
EvapHf	Calc	The total energy of the material evaporated from the precipatator, if evaporation is used.

Cooler Tab

Tag (Long/Short)	Input / Calc	Description/Calculated Variables / Options
FOR EMBEDDED COOLING OPTION
Cooler.On	tick box	Switches the cooler on/off
Cooling.Type	Fixed.dQ	User specifies the energy change required.
	Fixed.dT	User specifies the temperature change required.
	HeatExchange	User specifies the HTC, Area and flow for heat exchange.
Variables for the Fixed.dQ method
dQ	Input	The user specified change of energy.
Variables for the Fixed.dT method
dT	Input	The user specified change of temperature.
Variables for the HeatExchange method
HX.Area	Input	The user specified heat transfer area.
HX.HTC	Input	The user specified heat transfer coefficient.
By.Vol.Flow	tick box	Slurry to "cooler" can be specified in mass or volumetric flows
Heat Exchanger
Cooling.MassFlow / Cooling.Qm	Input / Calc	The slurry mass flow to be cooled by the "cooler". Input allowed when By.Vol.Flow is not selected.
Cooling.VolFlow / Cooling.Qv	Input / Calc	The slurry volumetric flow to be cooled by the "cooler". Input allowed when By.Vol.Flow is selected.
Hx.UA	Calc	heat exchanger UA.
Hx.LMTD	Calc	heat exchanger log mean temperature difference.
Liquor.Tin	Calc	The slurry temperature into the "cooler".
Liquor.Tout	Calc	The slurry temperature out of the "cooler".
Coolant
Water.Flow	Calc	Displays the CW mass flow into the "cooler" via the Cool_in connection.
Water.Vol.Flow	Calc	Displays the CW volumetric flow into the "cooler" via the Cool_in connection.
Water.Tin	Calc	Displays the CW temperature into the "cooler" via the Cool_in connection.
Water.Tout	Calc	Displays the CW temperature out of the "cooler" via the Cool_out connection.
Cooling.Rate	Calc	The rate of cooling.
FOR EXTERNAL COOLING OPTION
By.Vol.Flow	tick box	Slurry to "cooler" can be specified in mass or volumetric flows
Ext.Cooling.VolFlow / Ext.Cooling.Qv	Input / Calc	Input or displays the mass flow into the external cooler via the Cool_in connection, depends on the By.Vol.Flow option.
Ext.Cooling.MassFlow / Ext.Cooling.Qm	Input / Calc	Input or displays the mass flow into the external cooler via the Cool_in connection, depends on the By.Vol.Flow option.
Ext.Cooling.Temperature / Ext.Cooling.T	Calc	The temperature of the "cooled" side stream returning to the precipitator.
Ext.Cooling.TotHzOut	Calc	The total energy of the side stream leaving the precipitator.
Ext.Cooling.TotHzIn	Calc	The total energy of the side stream returning to the precipitator.
Cooling.Rate	Calc	The rate of cooling.

PSD Tab

Only visible when Precip.Method = PSD. Please See Precipitation using Full PSD for more information on theory and method.

Tag (Long/Short)	Input / Calc	Description/Calculated Variables / Options
PSDDefinition	List Box	Any predefined PSD definition in the project configuration file can be selected from this list.
PSD Control
Growth.On	Tick Box	Selecting this will enable growth rate calculation. Please see also Growth Rate Methods
Agglom.On	Tick Box	Selecting this will enable agglomeration calculation. Please see also Implementation of a size dependent kernel
Nucleation.On	Tick Box	Selecting this will enable nucleation rate calculation. [math]\displaystyle{ N = 5.0\times 10^8 \left(\frac{A-A^*}C\right)^2\sigma }[/math]
SodaWithNucleation	Tick Box	When this option is ticked, the bound soda calculations will be based on the total yield (growth + nucleation). If this is not ticked, the nucleation yield will be excluded in the bound soda calculations.
NonPSDSolids	Tick Box	Selecting this will include Non THA Solids in PSD Mass
AllSolidsDensity	Tick Box	Selecting this will include Non THA Solids in PSD Density
SeedPSD	Tick Box	Selecting this will allow SysCAD to auto generate a small quantity of seed if no THA solid was found in the Precipitation Feed. (In the case of a Dynamic Model, no THA solid present in the tank contents.) The generated amount will be sufficient to seed a tank and allow precipitation to occur in the tank. When solids returns to the tank via the proper seed streams, the recycled solids will take over and SysCAD will no longer generate any extra solids. See Using the Full PSD model.
Area.Correction	Input	Scaling for nonsphericity. See Area Correction
AcknowledgePSDOutletChange	Tick Box	Available from Build 139.30807. This checkbox will appear if the outlet Product stream had PSD action Create or Modify. Prior to this build, data from Create/Modify in the Product stream was able to affect the upstream unit model behaviour. Until this tickbox is checked to acknowledge the change, the model is unable to run. Model results will need to be reviewed and model may need to be retuned.
PSD Display
ShowRates	Tick Box	Selecting this will enable the display of Particle Size Number Data Table on the PSD tab. Please see Show Rates
DisplayAsFraction	Tick Box	When this option is ticked, the rates (Growth, Agglom, etc.) are normalised by dividing by the particle numbers: that is, displayed as a fraction of the particle number.
ShowAgglomKernel	Tick Box	Global option to show Kernel tab with agglomeration kernel beta terms. Note these values are the "raw kernel" before the inclusion of agglomeration rate or collision effects.
TrackUltrafines	Tick Box	Warn if mass is present in smallest size bin - this is moved to next bin up.
Agglomeration Parameters
Agglom.UseMidSize	Tick Box	Use PSD interval mid size (geometric mean) (checked) or top size (unchecked) for Agglomeration Kernel calculations. Only applicable for some options of Agglom.Kernel.Type.
Agglom.Kernel.Type	Size Independent	Ilievski size independent kernel (Light Metals, 1982). This assumes that all interactions are equally likely to cause an agglomeration event (i.e. beta = 1 for all size combinations). This option is typically paired with Agglom.Rate.Type Supersaturation.
	Ilievski	The kernel is of the form: [math]\displaystyle{ \frac {1}{D_{i}+D_{j}} }[/math]. See Size Dependent Kernel for more information. This option is typically paired with Agglom.Rate.Type of form Growth/Beta4. From Build 139, this is the default selection and [math]\displaystyle{ D_{i}+D_{j} }[/math] is replaced by [math]\displaystyle{ 2.\sqrt[m]{\frac{1}{2}(D_i^m+D_j^m)} }[/math], twice the Generalised Mean (see Wikipedia) of the interacting particle sizes with power [math]\displaystyle{ m }[/math] (Agglom.GenMeanPow). At default [math]\displaystyle{ m=1 }[/math] this is simply the sum.
	David-Rijkeboer	The kernel is of the form: [math]\displaystyle{ 1e9 \left( 1e9 \lambda_{trans}R_{L:T}\beta_{ij,L} + \left( 1 - \lambda_{trans} \right) \beta_{ij,T} \right) }[/math]. See David-Rijkeboer Kernel for more information.
	User	This option allows manual input of the agglomeration kernel on the dKernel tab.
	Kernel Builder	Enables the Kernel Builder, available on the dKernel tab.
Agglom.Rate.Type	Constant	The calculated agglomeration rate is set to 1, so in effect agglomeration rate is set directly using Agglom.Rate.Correction. This is equivalent to the option Agglom.RawKernel prior to Build 139.
	Supersaturation	The agglomeration rate is governed by a single equation dependant on temperature and liquor properties. Agglomeration rate is in the form: [math]\displaystyle{ 1.77\times 10^{-4} \times \left(\frac{A-A^*}C\right)^4 }[/math] . This option is typically paired with Agglom.Kernel.Type Size Independent.
	Growth/Beta4(T)	The agglomeration rate is of the form: [math]\displaystyle{ \frac {G^n}{\beta_4(T)} }[/math] where the calculated [math]\displaystyle{ \beta_4 }[/math] is a function of Temperature only. See Size Dependent Kernel for more information. This option is typically paired with Agglom.Kernel.Type Ilievski. From Build 139, this is the default selection.
	Growth/Beta4(T,Sh)	The agglomeration rate is of the form: [math]\displaystyle{ \frac {G^n}{\beta_4(T,Sh)} }[/math] where the calculated [math]\displaystyle{ \beta_4 }[/math] is a function of Temperature and Shear Rate. See Size Dependent Kernel for more information. This option is typically paired with Agglom.Kernel.Type Ilievski.
Agglom.Collision.Type	Restricted-in-Space	This option assumes a particle can only interact with particles in its immediate vicinity, restricting the number of possible collisions. Applies a division by total particle count [math]\displaystyle{ N_T }[/math] . See Free-in-Space vs Restricted-in-Space.
	Free-in-Space	This option assumes the agglomeration rate is proportional to the total number of possible collisions between particles, any particle is free to collide with any other particle. Applies a division by 109 (or 1012 prior to Build 139) to maintain a similar order of magnitude as Restricted-in-Space. See Free-in-Space vs Restricted-in-Space.
Agglom.UseCorrectedCollision	Tick Box	Available from Build 139. (For backwards compatibility, may be visible if upgrading projects). Simplifies the FIS and RIS corrections, as described above. Recommend this box be checked and model retuned as necessary.
Agglom.SolidsFracPow	Input	Power term for effect of solids volume fraction on agglomeration rate. Default 0.
Agglom.GrowthRatePow	Input	Used with Agglom.Rate.Type of form Growth/Beta4. Power term for effect of growth rate on agglomeration rate. Default 1.
Agglom.Cutoff	Tick Box	If selected, then particles greater than Agglom.Cutoff.Size will not agglomerate.
Agglom.Cutoff.Size	Input	Maximum size for agglomerating particles. Only visible when Agglom.Cutoff is selected.
Agglom.Cutoff.Used	Input	Actual size used for agglomerating particles. Only visible when Agglom.Cutoff is selected.
Agglom.GenMeanPow	Input	Available with Agglom.Kernel.Type David-Rijkeboer and David-Rijkeboer. Power term for Generalised Mean of particle size interactions. Default 1 to give arithmetic mean (i.e. proportional to sum). For Agglom.Kernel.Type David-Rijkeboer this applies to the Laminar portion.
Agglom.GenMeanPow2	Input	Available with Agglom.Kernel.Type David-Rijkeboer. As above. For Agglom.Kernel.Type David-Rijkeboer this applies to the Turbulent portion.
Agglom.DR.MinSize	Input	Available with Agglom.Kernel.Type David-Rijkeboer. The Batchelor microscale, below which no agglomeration occurs.
Agglom.DR.MaxSize	Input	Available with Agglom.Kernel.Type David-Rijkeboer. The Taylor microscale, above which no agglomeration occurs.
Agglom.DR.TransSize	Input	Available with Agglom.Kernel.Type David-Rijkeboer. The Kolmogorov microscale, where agglomeration transitions from laminar to turbulent regime.
Agglom.DR.TransSharp	Input	Available with Agglom.Kernel.Type David-Rijkeboer. Sharpness of the Kolmogorov transition.
Agglom.DR.LTRatio	Input	Available with Agglom.Kernel.Type David-Rijkeboer. Multiplier to correct the order of magnitude of the laminar kernel before summation with the turbulent kernel. Internally, a hard-coded 1e9 is applied, such that this user input should be close to 1.
Agglom.CalcBeta4	Tick Box	Used with Agglom.Rate.Type of form Growth/Beta4. Calculate (On) or user supplied (Off) [math]\displaystyle{ \beta_4 }[/math] in the Agglomeration Kernel equation.
Agglom.UserBeta4	Input	Used with Agglom.Rate.Type of form Growth/Beta4. User specified [math]\displaystyle{ \beta_4 }[/math] for use in the Agglomeration Kernel equation. Only visible when Calc.Beta4 is not selected.
Agglom.Beta4	Result	Used with Agglom.Rate.Type of form Growth/Beta4. [math]\displaystyle{ \beta_4 }[/math] in the Agglomeration Kernel equation. See Size Dependent Kernel
Agglom.Rate.Magnitude	Input	Overall correction of magnitude for Agglomeration calculations *10n. Default hidden, value 0. Used for coarse tuning only.
Agglom.Rate.Correction	Input	Overall correction rate for Agglomeration calculations.
Agglom.Rate.FineTuning	Input	Overall correction rate for Agglomeration calculations. Default hidden, value 1. Recommend to keep this term around 1.0 and use for localised fine-tuning.
Nucleation Parameters
Misra.Nucleation.Rate	Input	Nucleation Rate term, equivalent to [math]\displaystyle{ k \times e^{-E/RT} }[/math]. See Nucleation
Nucl.Rate.Correction	Input	Correction for Nucleation calculations
Results
Growth.Rate	Calc	Diametric (i.e. particle) growth rate. Same as GrowthRateD on the Precip tab.
Agglom.Rate	Calc	The total agglomeration rate factor determined by the selection of Agglom.Rate.Type and Agglomeration.Collision.Type (and associated inputs) as well as Agglom.Rate.Magnitude and Agglom.Rate.Correction. This term is multiplied with the kernel and particle sizes at each particle size combination. See Model Theory - Agglomeration.
Agglom.Degree	Calc	The degree of agglomeration at -45μm. Calculated as [math]\displaystyle{ \frac{[-45μm]_{Feed} \quad - \; \; [-45μm]_{Prod}} {[-45μm]_{Feed}} }[/math]
Nucleation.Rate	Calc	Net rate of increase in particle numbers due to nucleation.
GrowthYield	Calc	The Growth Yield. Total new mass of THA in tank due to Growth.
Nucleation.Yield	Calc	The Nucleation Yield. Total new mass of THA in tank due to Nucleation.
NumMassIn	Calc	Mass of PSD Solids into the Precipitation Tank (Excludes Non-PSD solids).
NumMassOut	Calc	Mass of PSD Solids leaving the Precipitation Tank.
Results (Particle Numbers)
NumbersByMassIn	Calc	Number of particles per mass of slurry entering the Precipitation tank.
NumbersByMassOut	Calc	Number of particles per mass of slurry leaving the Precipitation tank.
NumbersByMassDelta	Calc	The number of particles generated in the Precipitation tank per mass of slurry in the tank.
NumbersByVolIn	Calc	Number of particles per volume of slurry entering the Precipitation tank.
NumbersByVolOut	Calc	Number of particles per volume of slurry leaving the Precipitation tank.
NumbersByVolDelta	Calc	The number of particles generated in the Precipitation tank per volume of slurry in the tank.
NumbersBySolidsOut	Calc	The number of particles generated in the Precipitation tank per mass of PSD solids in the tank.

If ShowRates is selected, the following matrix of data with rates and numbers is shown:

Tag (Long/Short)	Description/Calculated Variables / Options
Particle Size Numbers Data
Particle Size Interval	Particle size interval as defined in the project configuration file. See Setting up the PSD Definition
MidSize	[math]\displaystyle{ Geometric Mean_i = \sqrt{d_i * d_{i-1}} }[/math], See Geometric Mean for more information.
#/kg Sl in	Particle numbers in incoming slurry
#/kg Sl tank	Particle numbers in the tank
GrowthRate	Net rate of increase in numbers due to growth
GrowthRate+	Rate of increase in numbers due to growth in from smaller bins
GrowthRate-	Rate of decrease due to growth out to larger bins.
AgglomRate	Net rate of increase in numbers due to agglomeration
AgglomRate+	Increase in numbers due to agglomeration from smaller bins
AgglomRate	Decrease due to agglomeration to larger bins
Tot.Rate	Agglom + Growth + Nucleation rates
Rate*ResT	Tot.Rate times Residence Time.
Ascending / Descending	Use the Ascending or Descending button to change the display order of the table.

Notes:

• The model ignores particles in the smallest bin (passing the smallest size), and will never create particles in this size. The feed may have particles of this size if the PSD is created using e.g. the Rosin-Ramler distribution. The TrackUltrafines option will warn when ultra-fine particles are present, and move them to the next smallest bin.

dKernel and Kernel Tabs

Only visible when Precip.Method = PSD.

Kernel tab only shown when ShowAgglomKernel is selected. This shows the full array of [math]\displaystyle{ \beta }[/math] kernel values.

dKernel tab only shown when Agglom.Kernel.Type = User or Kernel Builder. With Agglom.Kernel.Type = User, [math]\displaystyle{ \beta }[/math] values are manually entered for the entire agglomeration kernel.

With Agglom.Kernel.Type = Kernel Builder, the following fields are available for building a custom kernel function. See Kernel Builder for more details.

Form of each term: [math]\displaystyle{ a.\left(\cfrac{f(L_i,L_j,[m])}{b}\right)^n+c }[/math]

Tag (Long/Short)	Input / Calc	Description / Calculated Variables / Options
Kernel.Terms	Input	The number of terms in the agglomeration kernel calculation.
Kernel.Factor	Input	Overall correction factor for the calculated agglomeration kernel. Typically used to correct magnitude. Note that this term is optional, and has the same effect as Agglom.Rate.Correction.
The following are repeated for each Kernel.Terms. Note that Term# is replaced with Term1, Term2, etc.
Kernel.Term#.Type Form of [math]\displaystyle{ f(L_i,L_j,[m]) }[/math]	Sum	Sum of powers [math]\displaystyle{ L_i^m + L_j^m }[/math]
	Difference	Difference of powers [math]\displaystyle{ L_i^m - L_j^m }[/math]
	Product	Product [math]\displaystyle{ L_i.L_j }[/math]
	Maximum	Size of larger particle [math]\displaystyle{ L_i }[/math]
	Minimum	Size of smaller particle [math]\displaystyle{ L_j }[/math]
	Mean	Generalised mean [math]\displaystyle{ \sqrt[m]{\frac{1}{2}(L_i^m+L_j^m)} }[/math]
Kernel.Term#.Power	Input	Overall power n.
Kernel.Term#.PowerB	Input	Only available with Sum, Difference and Mean. Power on individual terms m.
Kernel.Term#.Coefficient	Input	Coefficient a.
Kernel.Term#.Divisor	Input	Divisor b.
Kernel.Term#.Constant	Input	Constant c.
Kernel.Term#.Denominator	Tick Box	Whether the term appears on the numerator (off) or denominator (on) of the kernel calculation.

Classif Tab

Only visible when Classification tick box is selected. The full Solid-Liquid Separator is used for General Separator and Evaporator, please see Solid-Liquid Separator for more information on theory and method. The Classification sub model uses most of the solid-liquid separator features. Difference and extra fields are documented here.

Tag (Long/Short)	Input / Calc	Description / Calculated Variables / Options
Requirements
SplitMethod	Solid Separation	This is the only available option as the embedded classifier will separate and recycle solids to meet target underflow solids concentration.
Requirements (Solids / Liquids Separation) Please see Solid Separation for all Solid Separation Methods.
The following is available when SolidsSeparaMethod = SolidsPSD.
SolidMethod	Whiten	This method is based on a model proposed by Whiten. See Whiten for information.
	Karra	This method is based on a model proposed by V.K Karra and is only valid for screen cut apertures greater than 1mm. See Karra for information.
	Rosin-Rammler	This method is based on a Rosin-Rammler type of function with the efficiency curve expression derived by Reid and Plitt. See Rosin-Rammler for information.
	Lynch	This method is based on a Lynch type of function. See Lynch for information.
	DelVillar-Finch	This method includes a term for the "fish hook" effect for entrainment. See DelVillar-Finch for information.
	Partition Curve	PartCrv Tab will open where user can define the Fraction of Feed Solids per size interval reporting to the oversize.
Selected Solid Species Calculation Method This section is used to set species Bypass options, (such as setting oxalate to bypass to O/F) , see Bypass Options for more information.
Results
Temperature	Calc	The temperature of the material leaving the classification section.
MassFlow / Qm	Calc	The mass flow feeding the classification section, this includes the internal recycle.
VapourMassFlow / VQm	Calc	The total flow of vapour to the Underflow and Overflow streams.
UF.BypassMassFlow / UF.BypassQm	Calc	The mass flow of the material that bypasses the underflow.
OF.BypassMassFlow / OF.BypassQm	Calc	The mass flow of the material that bypasses the overflow.
BypassMassFlow / BypassQm	Calc	The mass flow of the solids in the unit that bypasses the separation section.
UF.SolidsTakeoffQm	Calc	The internal solids recycle amount, displayed as solids mass flowrate. This is equivalent to the solids recycle stream on the Left image in Classification theory.
UF.SolidsTakeoffFrac	Calc	The internal solids recycle amount, displayed percent solids recycled. This is equivalent to the solids recycle stream on the Left image in Classification theory.
UF.FinalSolidFrac / UF.FinalSF	Calc	The final underflow solids fraction. This is after the recycle, thus the final underflow leaving the precipitation unit going forward.
Separation Results
UFSolidsRecovery	Calc	This is the internal classifier's underflow solids recovery, this is BEFORE the solids split to recycle. This is equivalent to the Classifier on the Left image in Classification theory.
UFLiquidRecovery	Calc	This is the internal classifier's underflow liquid recovery, this is BEFORE the solids split to recycle. This is equivalent to the Classifier on the Left image in Classification theory.

Content and Preset Tabs (Dynamic Only)

Content Tab: These displays the tank contents (total mass, volume, properties, etc.) in the standard Tank access window format.

Preset and DSp Tabs: allow the composition and contents to be preset.

Batch Tab (Probal Only)

Batch mode simulates a tank which is filled with separate PGL and Seed feed streams, allowed to precipitate, and then drained. In practice, a plant would have a number of tanks at different stages of the fill/precip/drain cycle, and the net operation is steady state; the contents of the product stream being determined by the composition at the end of batch cycle, and the flow rate determined by the total feed.

See Batch Mode for a more information.

Tag (Long/Short)	Input / Calc	Description/Calculated Variables / Options
Batch Operating Parameters
TankCount	Input	Number of Batch Tanks in the Precipitation bank (need not be integer)
Level.SetPoint / Level.Spt	Input	Operating Level of Batch Tank
PGL.VolFlowReqd / PGL.QvReqd	Input	PGL Fill Rate. The fill rate parameters can be different to actual PGL flow rates. If they are less, then we are filling multiple tanks simultaneously. If they are greater, then we are filling rapidly from a holding tank which is continuously filled from the feed streams.
Seed.VolFlowReqd / Seed.QvReqd	Input	Seed Fill Rate. The fill rate parameters can be different to actual seed flow rates. If they are less, then we are seeding multiple tanks simultaneously. If they are greater, then we are filling rapidly from a holding tank which is continuously filled from the feed streams.
Seed.Overlap	Input	Overlap of PGL and Seed. See Description of Batch Cycle for an illustration of fill time.
Drawoff.VolFlowReqd / Drawoff.QvReqd	Input	Drawoff Rate.
Drawoff.Overlap	Input
MaxResidenceTime	Input	Maximum residence time in a batch tank.
WaitTime	Input	After draining, there may be a specified wait time before filling starts again
Feed Flow Conditions
PGL.VolFlow / PGL.Qv	Result	Volume Flow of PGL.
Seed.VolFlow / Seed.Qv	Result	Volume Flow of Seed.
Calculated Cycle Times
Seed.Time	Result	Total Time spent seeding.
Drawoff.Time	Result	Total Time spent in drawoff.
Recirc.Time	Result	Total Time spent in precipitation.
AvailableCycleTime / Cycle.Time	Result	Overall Cycle Time. (Batch Cycle Done)
Waypoints: PGL Filling starts at t=0
PGL.EndTime	Result	PGL flow stopped.
Seed.StartTime	Result	Seed flow started.
Seed.EndTime	Result	Seed flow stopped.
Drawoff.StartTime	Result	Drawoff started.
Drawoff.EndTime	Result	Drawoff stopped.
TankFlowTime	Result	Feed Time per tank.
Levels during fill
SeedEndFirst	Result	Returns true if the Seed period ends before PGL filling.
Seed.StartLevel	Result	Level when seed started.
PGL.EndLevel	Result	Level when PGL stopped.
Seed.EndLevel	Result	Level when Seed stopped - generally equal to level setpoint.
Tank Masses
Seed.Mass / Seed.Mt	Result	Total Mass of Seed to tank.
Seed.Volume / Seed.Vt	Result	Total volume of Seed to tank.
Seed.SolidMass / Seed.SMt	Result	Total Solid Mass of Seed to tank.
PGL.Mass / PGL.Mt	Result	Total Mass of PGL to tank.
PGL.Volume / PGL.Vt	Result	Total volume of PGL to tank.
Total.Mass / Total.Mt	Result	Total Mass of PGL and Seed to tank.
Cooling
MinLevel	Input	Level where cooling is started/stopped.
Tank.VolFlow / Tank.Qv	Input	Flow of Cooling Water to Heat Exchange. This is the per tank cooling water flow.
Total.VolFlow / Total.Qv	Result	The calculated cooling water flow is determined by the batch model and the specified per tank cooling water flow. For correct prediction of the cooling water return temperature, the actual cooling water flow should be set to this calculated number. See Cooling form more inforamtion.
StartTime	Result	Cooling Initiated.
EndTime	Result	Cooling Ended.
Tank.TotalHeatXfer	Result	Batch Cycle Total Heat Transfer per Tank
Tank.AverageHeatLoad	Result	Batch Cycle Average Cooling Load per tank
Total.HeatLoad	Result	Total Cooling Load for all Tanks
EHX
Tank.TotalHeatXfer	Result	Batch Cycle Total Environmental Heat Loss per tank
Tank.AverageHeatLoad	Result	Batch Cycle Average Environmental Heat Loss per tank
Total.HeatLoad	Result	Total Environmental Heat Loss for all tanks.
Batch Control
Fill Steps	Input	Number of timesteps for fill. (Note: The default batch control parameters give sufficient accuracy for modelling.)
Recirc Steps	Input	Number of timesteps for recircirculation.
Drawoff Steps	Input	Number of timesteps for drawoff.

Cycle Tab (Batch Mode)

Tag (Long/Short)	Row / Column Heading	Description
Batch Data
T1 to T65	Row Heading	Time segments during a batch cycle, for each time segment, the following data are displayed.
Time / t	Col Heading	Time from start of filling
AC	Col Heading	The ratio of A:C, where A is NaAl[OH]4 concentration, expressed as grams of Al2O3 /L liquor and C is Caustic concentration in NaOH + NaAl[OH]4, expressed as grams Na2CO3/L liquor.
Solids	Col Heading	solids concentration.
Temp / T	Col Heading	tank temperature
Lvl	Col Heading	tank level
HX	Col Heading	cooling heat transfer
Rx	Col Heading	precipitation reaction heat
EHX	Col Heading	environmental heat transfer
SeedSol	Col Heading	seed solids flow
PrecSol	Col Heading	solids precipitation
PrecTHA	Col Heading	THA precipitation (excludes other solids)
TotSol	Col Heading	tank solids content - cumulative seed + precipitated solids
TotHt	Col Heading	total heat transfer (cooling + environmental heat transfer)